Question: $ F = \left[\begin{array}{rrr}2 & 1 & 2 \\ 0 & 2 & 0 \\ 1 & 2 & 2\end{array}\right]$ What is $ F^{-1}$ ?
Answer: $ = \left[\begin{array}{rrr}1 & \frac{1}{2} & -1 \\ 0 & \frac{1}{2} & 0 \\ -\frac{1}{2} & -\frac{3}{4} & 1\end{array}\right]$